2,967 research outputs found
B physics constraints on a flavor symmetric scalar model to account for the ttbar asymmetry and Wjj excess at CDF
Recently Nelson et al. proposed an interesting flavor symmetric model to
account for the top quark forward-backward asymmetry and the dijet anomaly at
CDF simultaneously with just three parameters: a coupling constant of order
one, and two scalar masses of 160 GeV and 220 GeV. However these fiducial
values of the parameters lead to the branching ratio of a almost pure penguin B
-> pi K decay about one hundred times larger than the experimental results.
Consider also the precision electroweak constraints, the scalar masses should
be at least around 500 GeV. Actually with the coupling constant larger than
one, it is impossible to explain either of the two CDF measurements
consistently in this model. But one may raise the charged scalar mass to, for
example, 250 GeV and reduce the coupling strength to 0.6 to meet the B physics
constraints. With this parameter set, the Wjj cross section is found to be in
the right range. But due to the scalar mass splitting, its correction to
T-parameter is about 3 sigma away from the precision electroweak constraints.
In addition, the top quark forward-backward asymmetry should be well below 0.1
with this small coupling constant.Comment: 9 pages, 2 figures, accepted for publication in Phys. Lett.
Improving Molecular Pretraining with Complementary Featurizations
Molecular pretraining, which learns molecular representations over massive
unlabeled data, has become a prominent paradigm to solve a variety of tasks in
computational chemistry and drug discovery. Recently, prosperous progress has
been made in molecular pretraining with different molecular featurizations,
including 1D SMILES strings, 2D graphs, and 3D geometries. However, the role of
molecular featurizations with their corresponding neural architectures in
molecular pretraining remains largely unexamined. In this paper, through two
case studies -- chirality classification and aromatic ring counting -- we first
demonstrate that different featurization techniques convey chemical information
differently. In light of this observation, we propose a simple and effective
MOlecular pretraining framework with COmplementary featurizations (MOCO). MOCO
comprehensively leverages multiple featurizations that complement each other
and outperforms existing state-of-the-art models that solely relies on one or
two featurizations on a wide range of molecular property prediction tasks.Comment: 24 pages, work in progres
Soft corneal contact lens for postoperative comfort in patients with recurrent pterygium function
AIM:To evaluate the effect of soft contact lens on the comfort of postoperative patients with recurrent pterygium. METHODS: For 100 eyes of 98 patients after recurrent pterygium excision, the conjunctival implant with limbal stem cells from the upper part of the cornea was used, and the scleral surface of the operation area was transferred and covered. Fifty eyes were treated with corneal bandage lens for 5d(Group A)and 50 eyes were conventionally ensheathed(Group B). The time of corneal wound healing and various symptoms and signs were observed after operation. RESULTS: Compared with Group B, 1d after pterygium, the symptoms and signs of corneal irritation in Group A were significantly less(PPCONCLUSION: The corneal contact lens can obviously improve the early postoperative corneal irritation in patients with pterygium, promote corneal wound healing and relieve postoperative discomfort
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